Nitrogenous organic compounds and processes of making same



Patented A aiv, 1945 Arthur W. Bur-well, Niagara Falls, N. Y., auignor to Alox Corporation, New York, N. Y., a com ration of New York No Drawing.. Application May '5, 164:, Serial No. 485,755

6 Claims. (oi. zoo-534) This invention relates to nitrogenou derivatives of substantially saturated, aliphatic hydroxy-carboxylic and/ or keto-carboxylic acids, to methods of making such nitrogenous derivatives,

and to compositions containing such nitrogenous derivatives. Specifically, the invention is concerned with the provision of nitrogenous deriva tives of the saturated aliphatic hydroxy carbo'xylic acids derived from mineral hydrocarbon mixtures (e. g., from petroleum oil or a liquid or. solid fraction thereof) by the controlled liquid;- phase partial oxidation of such a mixture by the procedure disclosed in U. S. Patent No. 1,690,769 to Arthur W. Burwell. L

While in the following description particular reference will be made to nitrogenous compounds derived from the substantially saturated hydroxy-carboxylic acid (and keto-carboxylic acid) mixtures produced by oxidation, by the Burwell process, of kerosene or 45 distillate, it is to be understood that the invention embraces also corresponding nitrogenous compounds produced e. g., 0.1% by weight, or of a non-acidic partial oxidation product rich in ketonic compounds obtained as a by-product ina, like oxidation procedure, or of both, is subjected to oxidation treatment at a temperature of 140 C. and at a pressure of 200 pounds per square inch by blowing therethrough a stream of air, and the oxidation from the petroleum acids from other normally liquid mineral hydrocarbons and from normally solid mineral hydrocarbons. Acid mixtures of the above-described'type may be obtained by a process which consists generally in the controlled, partial oxidation of mixtures of petroleum hydrocarbons, including petroleum waxes and petroleum distillates both light and heavy, by contacting the petroleum hydrocarbon mixture, in liquid phase, in the presence of an exciter of oxitreatment isv continued until the oxidation reac tion mass shows an acid number of about 50 (e. g., has an extractable acids content of from 25 to 'by weight); or, until incipient separation,

of products insoluble in the oxidation reaction mass is indicated in a test sample of the latter.

From the resulting reaction mixture, which contains a great number of diflerent, oxidation products oi petroleum hydrocarbons both acidic and non-acidic, the desired acid mixtures may be separated by one or another of the separation methods disclosed in U. S. Patent No. 1,981,822

to Arthur W. Burwell. The acid mixtures so p'roduced are, per se, valuable in rubber compoundi 18.

It, has now been found that certain nitrogenous derivatives of these acids have enhanced utility in rubber mixes adapted to be vulcanized by the .heat-and-pressure process and are otherwise useful. Methods of forming these nitrogeneous dedation, with an oxidizing gas such as air or oxygen-enriched air, at a reacting temperature above normal room temperature but not above 175? C., and at a superatmospheric pressure of from 150 to 350 pounds per square inch, under such conditions, including time, as to yield an optimum v content or the above-described acids while limiting the formation of oxidized compounds insoluble in the partially oxidized mass and in petroleum hydrocarbons, and the isolation of the aforesaid petroleum-soluble acids from the resulting partially oxidized mass.

A preferred mixture of acidic compounds for use in carrying into efiect the present invention is the product obtained by'carrying out the iol-' lowing process:

A body of commercially available petroleum distillate (whether'or not refined as to odor and/or color), having aspecific gravity of 45 Baum and known generally as 431-47- "kerosene to which has been added a suitable amount or a known oxidation catalyst, such as an or- "ganic salt of manganese. say, manganese oleate.

rivatives-hereinafter styled amino acids .or

amino acids mixturesoi the petroleum acidsmixtures will now be specifically described:

Exmmc I The starting material was a water-washed oxidation reaction mixture obtained by the controlled, liquid-phase, partial oxidation of 45 petroleum distillate carried to the point of incipient separation or products insoluble in the reactionmass.

Step 1 .The whole oxidation reaction mixture was treated, at elevated temperature, with an aqueous solution of caustic soda in an amount suiflcient to ensure completion of the saponification of all the saponifiable components of the mixture, whereby there were obtained (a) a supernatant oily layer containing unoxidized hydrocarbons and hydrocarbons which had been oxidized in- I sufliciently to have been converted into acids (i. e.,

unsaponiiiable alcoholic and ketonic products) but substantially no acidic compounds, and (b) a subnatant aqueous layer containing principally the sodium soaps of the acidic component or the oxidation reaction mixture, The oily layer was carefully drawn 01!, and was separately disposed boxylic acids.

separated from the coincidaitally produced aqueous sodium sulphate and was washed with water.

Step3 The resulting acids mixture was then thoroughly saturated with ammonia and progressively heated in'a still until the boiling point of the mass was reached, whereupon gaseous am monia was continuously bubbled through the mass while the latter was distilled; the end point of distillation was about 280 C. The distillate (largely crystalline when cool) was rich in ammonium salts of. amino acids and contained a. material amount of bodies answering to the tests of nitriles (alkyLC-EN) as well as some free acids.

step 4 The whole distillate was treated with dilute sulphuric acid, to remove the ammonia present in combination as ammonium salts and thus to free the acids. The supernatant clear layers of amino acids plus nitriles was separated from the subnatant ammonium sulphate solution and was carefully neutralized with aqueous caustic soda in the cold. The amino acids sodium soaps so produced were separated from the nitriles by the addition of water, and the neutral nitriles were floated oil and dried.

Step 5 The clear sodium soap product-freed from nitriles- -was then treated with dilute sulphuric acid, thereby liberating a mixture consisting essentially of amino acid derivatives of the original acids, which amino acids mixture was washed and dried.

The amino acids mixture soproduced was insoluble in water but soluble in hydrocarbons and other organic solvents of like nature. It was a normally liquid composition, light brown in color, and having a musty odor. The individual components of the amino acids mixture are believed to vary between a maximum molecular weight corresponding to a hydrocarbon of about 021 and a minimum molecular weight corresponding to a hydrocarbon of C5, with about 180 as an average molecular weight.

The nitriles separated during Step 4 above are useful as such; or, they may, by saponiflcation, be caused to revert to the corresponding car- I EXAMPLE II In this case, the procedure of Example I was repeated, but in Step 1 thereof the initial saponincation was eifected with ammonia instead of caustic soda. This modification did not affect the end results.

' Exmra III of Example I. The product diflered from that of Example I mainly by a higher degree of purity of amino acids in the "amino acids mixture product (i. e., it contained a smaller proportion of 5 non-acid oxidized products).

EXAMPLE IV The starting material was a water-washed oxidation reaction mixture obtained by the controlled, liquid-phase, partial oxidation of itemsene carried to the point at which the mass had an acid number of 50 and c'ontained to by weight of extractable acids.

The water-washed oxidation reaction mixture was thoroughly saturated with ammonia and was progressively heated in a still until the boiling point of the mass was reached, whereupon gaseous ammonia was continuously bubbled through the mass while the latter was distilled: the end point of the distillation was about 280 C.

The whole distillate was treated with aqueous caustic alkali (or equivalent saponifying agent), at elevated temperature, yielding (upon settling) a supernatant oily layer, consisting essentially of unoxidized hydrocarbons and unsaponifiable oxidized hydrocarbons, and a subnatant aqueous layer containing sodium soaps of the amino acids content of the distillate. The latter layer was separated from the oily layer and was treated a with dilute sulphuric acid in amount just sufficient to decompose said sodium soaps. The sofreed amino acids-rich mixture was separated from the resulting aqueous layer, was washed, and dried.

5 The choice as among the methods of Examples I through IV is largely an economic one, to be determined by the purity requirements in any I particular case. It is to be understood that in each of Examples I through IV the final product is'a mixture of compounds including mainly the aforesaid amino acids, with smaller or larger amounts of associated oxidized hydrocarbons (e. g., compounds answering to the tests for diamino carboxylic acids, for acid amids, and for dimeric and trimeric alcohol condensation products of amino acids and acid amids).

The step of distilling the ammonia-saturated petroleum acids mixture while passing ammonia through the distilland may be practiced at a pressure somewhat less than atmospheric: or, as where the components are of very low molecular weights, the distillation may be practiced at superatmospheric pressure.

As was indicated hereinbefore, the procedures Just described may be practiced on other petroleum fractions than the 45 distillate, or kerosene, chosen for the specific examples, yielding thereby amino acids mixtures and nitrile-rich mixtures which differ from the products speciflcally described above in that the molecular weights of the components of the products will vary with the molecular weights of the hydrocar bons composing the starting material, and/or with the distilling range of the bodies removed.

The amino acids mixtures of the present invention, when added to rubber mixes adapted to be vulcanized by the heat-and-pressure method, function to prevent scorching of the mix; also, to activate the accelerator and zinc oxide, and 1 as an anti-oxidant during use of the vulcanized rubber product. The amino acids mixtures are useful also in the preparation of penetrating oils and of certain anti-corrosives. I

' Because of the fact that the acids-rich startins material is itself a mixture of a large numasvaasa ber oi diiierent compounds, and'because the procedural steps or the nitrogen-adding process still further add to the complexity of the resulting products, I am unable to identiiy,'and

myii-slk i-o H alkyl-I-alkyl-COOH n o H NH: oi which the compound I CHS-(CHQl-CHNHj-(CHflI-CO0H is illustrative;

Di-amino acids, from dihydroxy carboxylic' n a alkyl-JJ-alkyl--slkyl-COQH 2820 NB: NE, of which the compound OKs-CH2.CHNH1.(CH|) .CHNH:.(01191.000E

is illustrative and Dimeric and trimeric aldol condensation amino acids, from keto acids: 1

NH: NH| alkyl-Jl-CHM} 0.slkyl Haslkyl. C 0 0H (dimeric condensation) and ' alkyl.C0.NHz

alkyl- ----on,

11111. ='o alk l-d- H:

kyLCONH:

in the original acids mixture. 'I'hatis to say, my researches l ad me to believe that in the distillation treatment the hydroxy-carboxylic acids largely tend to lose the chain-OH group, and tend, therefore, to polymerize at the chain carbon so relieved.

This application contains subject-matter in common with, and is a continuation-in-part of, my application Serial No. 383,434, filed March 14, 1941.

I claim:

1. Process of modifying petroleum acids characterired by the constitution alkyl-R-alkrl-COOH wherein R, represents a bivalent group selected from the group consisting of tat H a said acids having an average molecular weight Analyses indicate that the compositions contain one (or slightly more than one) atom oi ni- I hydroxylated hydrosy-carboxylic acids cditained of from to about and ranging from 6 to 21 carbon atomsper molecule which comprises treating with ammonia a body of water-insoluble oxygenated compounds consisting essentially of said petroleum acids, maintained at an elevated temperature, distilling the so-treated body while simultaneously passing ammonia through the distilland, and removing water and nitrile-likebodies from the resulting distillate.

2. Process oi modifying petroleum acids characterized by the constitution wherein -R- represents a bivalent group select-v ed from the group consisting of said acids having an average molecular weight of from 160 to about 180 and ranging from 6 to 21 carbon atoms per molecule which comprises treating with ammonia a 'body, of water-insoluble oxygenated compounds consisting essentially of said petroleum acids, distilling the so-treated body while simultaneously passingammonia through the distilland, treating the distillate with a saponiiying agent in aqueous medium, separating the resulting aqueous layer from the resulting non-aqueous layer, and thereafter treating the aqueous layer with mineral acid in amount lust suillcient to decompose soaps.

3. Process of modify g a mixture of hydroxy carboxylic' acids, keto carboxylic acids and carboxylic acids oi the general formula H H alkyl-C-alkyl-C-slkyl-C O OH having an average 'molecularweight, 01 from 160 to about 180 and ranging from 6 to 21 carbon atoms per molecule, derived irom a fraction of petroleum by liquid-phase partial oxidation of the latter, which comprises treating with ammonia a body or water-insoluble oxygenated *compounds consisting essentially of said petroleum acids, distilling the so-treated body while simultaneously passing ammonia through the distilland, treating the distillate with aqueous mineral acid in amount suflicient to decompose any ammonium soaps present in the distillate, separating the reaction mixture into an aqueous portion and a non-aqueous portion, treating the nonaqueous portion in the cold with a saponiiying product until substantially free from tree mineral acid and mineral acid salts, and drying the product.

4. Process of modifying petroleum acids characterlzed by the constitution alkyl-R-alkyl-COOH asra'ess atoms intermediate the terminal carbon atoms .of the aliphatic radicals there being present more than 1 but less than 2 atoms of nitrogen per molecule of the acids, said mixture being obtained from a mixture rich in a plurality of different aliphatic carboxyiic acids of petroleum origin ranging from 6 to 21 carbon atoms per wherein -R- represents a bivalentsro p selected from the group consisting of n n n -o-, -o-, and -0.alkyl.0 An 11 a said acids having an average molecular weight of from 160 to about 180 and ranging from 6 to 21 carbon atoms per molecule which comprises treating with ammonia a body 01' water-insoluble oxygenated compounds consisting essentially oi said petroleum acids, distilling the so-treated body while simultaneously passing ammonia through the distilland, treating the distillate with aqueous mineral acid in amount sufllcient to decompose any ammonium soaps present in the distillate, separating the reaction mixture into an aqueous portion and a non-aqueous portion, treating the non-aqueous portion in the cold with a saponiiying agent in aqueous medium, separating the resulting aqueous layer from the resulting non-aqueous layer, thereafter treating the aqueous layer with mineral acid in amount just sufficient to decompose soaps, washing the resulting water-insoluble -product until substantially free from free mineral acid and mineral acid salts, and drying the product.

5. The process defined in claim 1, in which prior to the step of treating the petroleum acids mixture with ammonia the former is subjected to a distillation treatment for removal therefrom of compounds tending to yield tarry by-products.

6. As a new product, a composition essentially consisting of a mixture of different aliphatic carboxylic acids, ranging from 6 to 21 carbon atoms per-molecule and having an average molecular weight between 180 and about 180, said acids containing amino groups attached to carbon molecule and having an average molecular weight between 160 and about 180, said acids having the general constitution alkylR-alkylCO0H wherein R- represents a bivalent group selected from the group consisting of and including a substantial proportion of acids of the general constitution 3 layer and a subnatant aqueous layer which latter is separated from the supernatant oily layer and discarded, neutralizing the oily layer with aqueous alkali in the cold to form alkali metal soaps of the acids'present therein and diluting with water to separate any water-insoluble components, treating the aqueous soaps solution with dilute mineral acid in amount suiilcient to decompose the soaps, and separating the so-liberated acids mixture from aqueous medium, said composition being additionally characterized-in that it is a brown liquid of musty odor and in that its presence in a rubber mix tends to prevent scorching of the mix and to retard oxidation of the vulcanizate. ARTHUR. W. BURWELL. 

